The issue of accompanying antisubmarine executed by multiple antisubmarine helicopters in naval ship formation ferry process was studied.Based on analysis to torpedo firing distance,we established torpedo attack position models for ideal condition and formation evasion maneuver condition,and obtained the antisubmarine configuration position.Then,the multi-aircraft accompanying antisubmarine methods were analyzed,and models were built up to calculate detection probability and the needed antisubmarine force.Finally,simulation was made to analyze the submarine torpedo firing position,and the effect of antisubmarine helicopter quantity,detection times,antisubmarine area size on the detection probability.The results show that: 1) The appropriate quantity of antisubmarine helicopter is three;and 2) The accompanying antisubmarine area should be set at 20 n miles in front of the formation with the size of 20 n mile×30 n mile.